The hard disk drive comprises: a magnetic disk 2 having servo information
stored; magnetic heads 4 seeking on the magnetic disk 2 and staying
at a predetermined position to read or write data; a voice coil motor 6 moving
the magnetic heads 4 to the predetermined position of the magnetic disk
2; a position controller supplying a driving current to the voice coil motor
6 based on the servo information read by the magnetic heads 4. The
position controller includes: a CPU 12 outputting a speed control value
based on the servo information; a DAC 7 and a VCM driver 8 converting
the speed control value into the driving current; and a controller 10 limiting
a driving speed of the voice coil motor 6 in a case that an output timing
of the speed control value is shifted.
